The major purpose of this study is to determine the characteristics associated with those Health Maintenance Organization (HMO) projects which have made progress towards operational viability. In addition, the study will provide a timely and relevant evaluation of P.L. 93-222, the HMO Act of 1973, and its administration by the Department of Health and Human Services. The population of plans under examination consists of new-start HMO projects that received grant funding under P.L. 93-222 from the initiation of funding until the end of FY 1977. It is possible to determine how these projects fared in each of the developmental stages of the Federal model, feasibility, planning, initial development, and in the operational stage. A number of hypotheses relating to the HMO project itself (e.g., sponsor commitment, presence of a committed person or group and good management resource capability, both at the plan management level and at the Board level, level of organization and facility and provider arrangements), one hypothesis relating to the project and the environment (ability of the HMO to offer a competitive premium), and several hypotheses relating to the environment (adequate population base in area, characteristics of current delivery system, attractiveness of the group health insurance market--including the stance of both industry and unions, and program implementation factors) are to be tested in the study. Data are being collected chiefly from data available from the Office of HMOs: application files for grants, loans, and qualification, pre-collected quarterly reports on operational plans, and annual program status reports. Additional data are to be collected from individual HMOs and Regional Office contract officers. Data will be analyzed to examine the relationship between the independent variables and the dependent variable. Study results will provide information for planning, administrative decision-making and public policy formulation: there may be some relevance of the conclusions for the 1981 Congressional hearings covering the HMO development program, and ensuing HMO Amendments.